JP2011254114A - Electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic device capable of protecting an electronic component element by finely shielding electromagnetic waves without a shield case, and corresponding to slimming down.SOLUTION: The electronic device comprises a wiring substrate 1, an electronic component element 4 mounted on the wiring substrate 1, a resin material 2 covering the electronic component element 4 and provided on the wiring substrate 1, a ground electrode pattern 5 positioned at an outer periphery portion of the wiring substrate 1, and a shield layer 3 provided on an upper surface of the resin material 2. The wiring substrate 1 is obtained by dividing a large-sized substrate from which multiple pieces can be taken in a state that the ground electrode pattern 5 is provided. An outer periphery portion of the shield layer 3 is extended onto the ground electrode pattern 5 positioned at the outer periphery portion of the wiring substrate 1, and electrically connected to the ground electrode pattern 5 at an extension part.

Description

  The present invention relates to a communication device such as a mobile phone and a personal computer, and an electronic device incorporated in the electronic device.

  Conventionally, an electronic device provided with a high-frequency circuit is used in communication equipment such as a mobile phone.

  As such a conventional electronic device, for example, as shown in FIG. 4, a high frequency circuit, a ground wiring or the like is embedded in a wiring substrate 21 formed by laminating a plurality of insulating layers, and an IC is formed on the upper surface of the wiring substrate 21. An electronic component element 23 such as an element, a chip inductor, a chip capacitor, a diode, or a chip resistor is mounted, and a metal shield case 22 is attached so as to cover the electronic component element 23. (For example, refer to Patent Document 1).

  The shield case 22 is for electromagnetically shielding the electronic component element 23 by holding it at a ground potential when the electronic device is used. As a result, the electromagnetic characteristics from the outside can be shielded to stabilize the circuit characteristics of the electronic device, and the electronic component element 23 can be operated normally. Such a shield case 22 has, for example, a housing shape with an opening on one surface, and a constant gap between the shield case 21 and the electronic component element 23 so that the shield case 21 and the electronic component element 23 do not come into contact with each other. It is attached to the wiring board 21 with a space provided.

Japanese Patent Laid-Open No. 2001-196781

  By the way, in the conventional electronic device described above, when the shield case 21 is attached, the shield case may be tilted or the mounting position may vary. In consideration of these, the shield case 21 -the electronic component element 23. It is necessary to design so that a certain amount of space is provided between them. However, if a certain amount of space is provided between the shield case 21 and the electronic component element 23, an extra space is generated correspondingly, resulting in a problem that the electronic device becomes taller.

  The present invention has been devised in view of the above-mentioned problems, and the object thereof is to protect an electronic component element by properly shielding electromagnetic waves without using a shield case, and to cope with a reduction in thickness. An object of the present invention is to provide an electronic device capable of performing the above.

According to one aspect of the present invention, an electronic device includes a wiring board, an electronic component element mounted on the wiring board, a resin that covers the electronic component element and is provided on the wiring board. A material, a ground electrode pattern located on the outer periphery of the wiring board, and a shield layer provided on the upper surface of the resin material. The wiring board is obtained by dividing a large-sized board that can be taken in large numbers with the ground electrode pattern provided. The outer peripheral portion of the shield layer extends to the ground electrode pattern located on the outer peripheral portion of the wiring board, and is electrically connected to the ground electrode pattern at the extended portion.

  According to one aspect of the present invention, the electronic device includes the shield layer provided from the upper surface to the side surface of the resin material, thereby shielding electromagnetic waves without providing a shield case, thereby improving the circuit characteristics of the electronic device. It is possible to stabilize the electronic component element and to operate it normally.

It is sectional drawing of the electronic device of this invention. FIG. 3 is a cross-sectional view of a main part in which the first resin material 2 and the second resin material 3 of the electronic device of FIG. It is sectional drawing of the electronic device which concerns on other embodiment of this invention. It is sectional drawing of the conventional electronic device.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view of an electronic device according to an embodiment of the present invention. The electronic device shown in FIG. 1 is roughly composed of a wiring board 1, a first resin material 2, and a second resin material 3. Has been.

  The wiring board 1 is constituted by a substantially rectangular laminate formed by laminating a plurality of insulating layers in the thickness direction, and a large number of circuit wirings 6 are interposed between these insulating layers. Are electrically connected to each other via via hole conductors 7 embedded in the insulating layer.

  As a material of the insulating layer constituting such a wiring board 1, for example, a ceramic material such as glass ceramics is used, and the thickness of each insulating layer is set to 50 μm to 300 μm, for example.

  When the insulating layer is made of a ceramic material, the wiring board 1 is formed by laminating a plurality of ceramic green sheets obtained by adding and mixing an appropriate organic solvent, organic solvent, etc. to the ceramic raw material powder. The laminate is manufactured by press molding and then firing the laminate at a high temperature and processing the outer shape.

  Moreover, as a material of the circuit wiring 6 and the via-hole conductor 7 provided in the wiring board 1, for example, a conductive material mainly composed of silver is preferably used, and the thickness of each circuit wiring is, for example, 5 μm to It is set to 20 μm.

  On the other hand, the main surface of the wiring board 1 is provided with a ground electrode pattern 5, connection pads 8 connected to the circuit wiring 6, and surface wiring (not shown).

  The ground electrode pattern 5 is arranged in an annular shape along the outer periphery of the upper surface of the wiring board 1, and is an external connection conductor (not shown) formed on the side surface of the wiring board 1 via the via-hole conductor 7 and the like inside the wiring board 1. Connected to. The external connection conductor is electrically connected to a ground wiring provided on a motherboard on which the electronic device is mounted, so that the ground wiring pattern 5 is held at the ground potential when the electronic device is used. It has become.

The ground electrode pattern 5 and the connection pad 8 contain, for example, an Ag-based powder such as Ag, Ag-Pd, or Ag-Pt, a borosilicate-based low-melting glass frit, an organic binder such as ethyl cellulose, an organic solvent, or the like. The conductive paste is formed on a ceramic green sheet corresponding to the uppermost layer of the wiring substrate 1 by screen printing or the like, and is fired.

  Further, the thickness of the ground electrode pattern 5 is set to, for example, 5 μm to 80 μm. Particularly, if the thickness is set to 50 μm or more, before the liquid resin is applied in forming the first resin material 2 described later, The liquid resin also serves as a dam that blocks the liquid resin from flowing out from the upper surface of the wiring board 1. Therefore, when the first resin material is formed, when the liquid resin having low viscosity and easy to flow is used, the thickness of the ground electrode pattern 5 is preferably set to 50 μm or more.

  On the upper surface of the wiring substrate 1, an electronic component element 4 such as an integrated circuit component element, a chip inductor, a chip capacitor, a chip resistor, or a diode is mounted.

  The electronic component element 4 is electrically connected to a connection pad 8 attached to the upper surface of the wiring board 1 via a conductive adhesive such as solder, and the electronic component element 4 and a circuit inside the wiring board 1 are connected. The wiring 6 constitutes a predetermined electric circuit. In the present embodiment, one electronic component element 4 is mounted on the wiring board 1.

  The electronic component element 4 is sequentially covered with a first resin material 2 having electrical insulation and a second resin material 3 having conductivity.

  The first resin material 2 includes a protective film that protects the electronic component element 4 from external impact, an insulating film that prevents the second resin material and the electronic component element 4 from being short-circuited, and the electronic component element 4. It has a function as a sealing layer for hermetically sealing.

  In addition, such a first resin material 2 is obtained by adding and mixing a thermosetting resin such as an epoxy resin with a curing agent, a curing accelerator, and other inorganic fillers if necessary. The electronic component element 4 is applied so as to cover the electronic component element 4 by a method or the like, and then heated and cured. The distance from the upper surface of the electronic component element 4 to the upper surface of the first resin material 2 is, for example, 0.10 mm to It is set to be in the range of 0.30 mm.

  On the other hand, the second resin material 3 is electrically connected to the ground electrode pattern 5 of the wiring board 1, and when the electronic device is used, the second resin material 3 is held at the ground potential, thereby causing an electromagnetic wave from the outside. It is possible to stabilize the circuit characteristics of the electronic device and to make the electronic component element operate normally. In addition, in this case, since it is not necessary to secure an extra space between the shield case and the electronic component element as in the conventional electronic device, the electronic device can be thinned.

  Such a second resin material 3 is made of, for example, the same epoxy resin as the first resin material described above, or conductive particles such as Au, Ag, Cu, and a curing agent on a resin such as a silicon resin or a polyimide resin, By applying a curing accelerator and other inorganic fillers added and mixed as necessary, by covering the first resin material by a conventionally known screen printing method, etc., and then thermally curing. It is formed and its thickness is set to 0.05 mm to 0.20 mm, for example.

  In addition, content of the said electroconductive particle is set to the range of 75-88 wt% with respect to the weight of the whole 2nd resin material, for example.

In addition, since the outer peripheral portion of the second resin material 3 is connected to the annular ground electrode pattern 5 that surrounds the mounting area of the electronic component element 4, the entire second resin material is used when the electronic device is used. It is possible to reliably hold the ground potential, enhance the shielding effect of electromagnetic waves, make the electronic device operate more stably, and effectively influence the influence of external electromagnetic waves on the electronic component elements It becomes possible to suppress. Therefore, it is preferable to arrange the second resin material 3 so that the outer peripheral portion thereof is connected to the ground electrode pattern 5.

  Further, as shown in FIG. 2, the ground electrode pattern 5 has a notch 9 at a corner portion between the upper surface and the inner peripheral surface, and the outer peripheral portion of the second resin material 3 is provided with the notch 9. Since it is arranged so as to coincide with the corner portion 10 formed between the inner surface and the upper surface of the ground electrode pattern 5 to be configured, the contact area between the second resin material 3 and the ground electrode pattern 5 is increased, The adhesion strength between the second resin material 3 and the ground electrode pattern 5 can be improved to improve the airtightness of the electronic component element 4.

  Further, by providing the notch 9 as described above in the ground electrode pattern 5, when the liquid resin is applied when forming the second resin material 3, the liquid resin before curing flows out from the upper surface of the wiring substrate 1. It can also be blocked.

  Thus, in the electronic device described above, the electronic component element 4 mounted on the wiring board 1 is covered with the first resin material 2 having electrical insulation, and the first resin material 2 is covered with the second resin material 3 having conductivity. By covering, an electromagnetic wave from the outside can be shielded by the second resin material 3 having conductivity without using a shield case, and the electronic device can be operated stably.

  In addition, this invention is not limited to the above-mentioned embodiment, A various change and improvement are possible within the range which does not deviate from the summary of this invention.

  In the above-described embodiment, the ground electrode pattern 5 is arranged so that the outer peripheral edge thereof matches the outer peripheral edge of the upper surface of the wiring board 1. Instead, the outer peripheral edge of the ground electrode pattern 5 is replaced with the wiring board 1. You may make it arrange | position by a predetermined distance apart inside the outer peripheral edge. In this way, even when the wiring board 1 is manufactured by the “multi-piece” method by dividing the large substrate, the ground electrode pattern 5 and the cutting cutter are separated at the time of dividing / cutting the large substrate. Since there is no contact, there is no inconvenience that the edge of the ground electrode pattern 5 is peeled off from the base when the large substrate is cut.

  In the above-described embodiment, the electronic component element 4 is electrically connected to the connection pad 8 provided on the upper surface of the wiring board 1 via a conductive adhesive such as solder. Instead, as shown in FIG. 3, it may be electrically connected to the connection pad 8 via a bonding material 11 such as a fine metal wire. In this case, it is important to cover the bonding material 11 together with the electronic component element 4 with the first resin material 2.

  Furthermore, in the above-described embodiment, one electronic component element 4 is mounted on the wiring board 1, but it goes without saying that a plurality of electronic component elements 4 may be mounted. In that case, it is preferable that the upper surface of the tallest electronic component element among the plurality of electronic component elements 4 is separated from the upper surface of the first resin material by, for example, about 0.10 mm to 0.30 mm.

  Furthermore, in the above-described embodiment, the wiring substrate 1 is formed of glass ceramics. Instead, other ceramic materials such as alumina ceramics or organic materials such as glass cloth base epoxy resins are used. Thus, the wiring substrate 1 may be formed.

In the electronic device, an electronic component element covered with an electrically insulating first resin material is covered with a conductive second resin material, and the second resin material is electrically connected to the ground electrode pattern. Therefore, when the electronic device is used, by holding the second resin material at the ground potential, the electromagnetic characteristics can be shielded without providing a shielding case to stabilize the circuit characteristics of the electronic device and the electronic component element operates normally. To be able to. In addition, in this case, since it is not necessary to secure an extra space between the shield case and the electronic component element as in the conventional electronic device, the electronic device can be thinned.

  In addition, since the outer peripheral portion of the second resin material is connected to the annular ground electrode pattern surrounding the mounting area of the electronic component element, the entire second resin material can be surely used when the electronic device is used. It can be held at the ground potential, enhances the shielding effect of electromagnetic waves, makes electronic devices operate more stably, and effectively suppresses the influence of external electromagnetic waves on electronic component elements Is possible.

  Further, the electronic device forms a notch at a corner between the upper surface and the inner peripheral surface of the ground electrode pattern, and the outer peripheral portion of the second resin material is formed on the inner surface and the upper surface of the ground electrode pattern constituting the notch. The contact area between the second resin material and the ground electrode pattern is increased, and the adhesion strength between the second resin material and the ground electrode pattern is improved to match the position of the corner formed between The airtightness of the component element can be improved.

DESCRIPTION OF SYMBOLS 1 ... Wiring board 2 ... 1st resin material 3 ... 2nd resin material 4 ... Electronic component element 5 ... Ground electrode pattern

Claims (1)

A wiring board;
An electronic component element mounted on the wiring board;
While covering the electronic component element, and a resin material provided on the wiring board,
A ground electrode pattern located on the outer periphery of the wiring board;
A shield layer provided on the upper surface of the resin material,
The wiring board is obtained by dividing a large-sized board capable of taking a large number in a state where the ground electrode pattern is provided,
The outer peripheral portion of the shield layer extends to the ground electrode pattern located on the outer peripheral portion of the wiring board, and is electrically connected to the ground electrode pattern at the extended portion. An electronic device.

Images